3 files changed, 26 insertions, 0 deletions
diff --git a/lib/sockunion.c b/lib/sockunion.c
index 6a40f332..d1f6d80b 100644
--- a/lib/sockunion.c
+++ b/lib/sockunion.c
@@ -527,6 +527,30 @@ sockopt_ttl (int family, int sock, int ttl)
   return 0;
 }
 
+int
+sockopt_v6only (int family, int sock)
+{
+  int ret, on = 1;
+
+#ifdef HAVE_IPV6
+#ifdef IPV6_V6ONLY
+  if (family == AF_INET6)
+    {
+      ret = setsockopt (sock, IPPROTO_IPV6, IPV6_V6ONLY,
+			(void *) &on, sizeof (int));
+      if (ret < 0)
+	{
+	  zlog (NULL, LOG_WARNING, "can't set sockopt IPV6_V6ONLY "
+		    "to socket %d", sock);
+	  return -1;
+	}
+      return 0;
+    }
+#endif /* IPV6_V6ONLY */
+#endif /* HAVE_IPV6 */
+  return 0;
+}
+
 /* If same family and same prefix return 1. */
 int
 sockunion_same (union sockunion *su1, union sockunion *su2)
diff --git a/lib/sockunion.h b/lib/sockunion.h
index 96b9a0d4..db145cf2 100644
--- a/lib/sockunion.h
+++ b/lib/sockunion.h
@@ -99,6 +99,7 @@ extern int sockunion_accept (int sock, union sockunion *);
 extern int sockunion_stream_socket (union sockunion *);
 extern int sockopt_reuseaddr (int);
 extern int sockopt_reuseport (int);
+extern int sockopt_v6only (int family, int sock);
 extern int sockunion_bind (int sock, union sockunion *, 
                            unsigned short, union sockunion *);
 extern int sockopt_ttl (int family, int sock, int ttl);
diff --git a/lib/vty.c b/lib/vty.c
index bd1dbac0..e403159b 100644
--- a/lib/vty.c
+++ b/lib/vty.c
@@ -1816,6 +1816,7 @@ vty_serv_sock_addrinfo (const char *hostname, unsigned short port)
       if (sock < 0)
 	continue;
 
+      sockopt_v6only (ainfo->ai_family, sock);
       sockopt_reuseaddr (sock);
       sockopt_reuseport (sock);